Chimaerism, Mosaicism, and Forensic DNA Analysis

Abstract

Greek mythology is filled with examples of beings made of mixtures of several creatures fused together to form a single one. Perhaps the best example of this was a combination of lion, goat and serpent, known as the Chimaera. Today the term has come to describe organisms composed of two or more different, genetically distinct cell lines. For scientists involved in forensic DNA testing this concept is troubling as the analysis of such individuals would lead to spurious results that could be problematic to interpret. It is therefore important to understand what chimaerism is, how prevalent it is in the population and ultimately how this may affect the outcome of forensic DNA testing. This paper will explore the literature surrounding this phenomenon and propose some answers to the questions that arise. RÉSUMÉ La mythologie grecque est remplie d'exemples d'êtres formés d'une fusion de plusieurs créatures pour n'en faire qu'une. Un bon exemple est la combinaison d'un lion, d'une chèvre et d'un serpent pour former la chimère. De nos jours, ce terme désigne des organismes formés de deux ou plusieurs différentes lignes de cellules génétiquement distinctes. Pour les scientifiques effectuant des tests d'identité parl'ADN, ce concept est préoccupant puisque l'analyse de tels individus mènerait à de résultats spécieux qui s'avèreraient difficiles à interpréter. Il est donc primordial de comprendre ce qu'est le chimérisme, à quel point il est répandu dans la population et en bout de ligne, comment ceci affecterait les résultats de l'identité par ADN. Cet article examinera la littérature se rapportant à ce phénomène et suggèrera quelques réponses aux questions qui émergent.

Isolation and quantification of DNA from epithelial cells obtained from acrylic removable partial denture for sex identification

“…Though SRY gene is validated as an ideal sex-determining marker in the present study, there are few conditions in which SRY gene cannot be amplified, thereby leading to discrepancies between the genetic sex and phenotypical sex. These conditions are Turner syndrome (46,X0), Klinefelter syndrome (46,XXY), androgen insensitivity syndrome, Swyer syndrome caused by a mutation of SRY gene, 46,XX testicular disorder of sex development associated with the SRY gene, 47,XYY syndrome, 5-alpha-reductase deficiency, chimaerism and microchimaerism (Shahid et al 2010;Poplinski et al 2010;Audi et al 2010;Knower et al 2011;Wang et al 2004;Sunami et al 2010;Walker 2008;Bianchi et al 1996;Benito et al 2004).…”